The present invention relates to a catalytic converter for processing gases and, more particularly, to a catalytic converter for use with automobiles for purifying exhaust gases from automobile engines.
Catalytic converters are often used in modern automobiles as a means for accomplishing purification of exhaust gases from engines. A catalytic converter for this purpose generally comprises a housing means having inlet and outlet ports and defining a gas flow passage extending therethrough from said inlet port to said outlet port, and a catalyst material such as grain catalyst charged in said housing means to be traversed by said gas flow. The catalyst material is of an oxidizing type in some cases while it is of a reducing type in other cases. Furthermore, a 3-way catalyst having oxidizing and reducing performance is also known and used.
In automobiles, a catalytic converter is incorporated at a middle portion of an exhaust system of an engine, and is traversed by hot exhaust gases. Therefore such a catalytic converter is liable to become hot during operation. Especially when a catalytic converter is of an oxidizing type, the bed of catalyst becomes relatively hot and, consequently, the casing, the separators for holding pellets of catalyst, and other structural members forming the housing of the converter also become relatively hot. Because of this high temperature condition to which the housing structural members are subjected, it is desirable that the structural members, particularly the separators, which are heated to the highest temperature of all, should be designed to be able to undergo relatively free thermal expansion and contraction.
A catalytic converter of a radial flow type includes a housing which generally comprises an outer casing, an outer separator formed as a cylindrical element having a large number of small openings and mounted in said outer casing so as to define an outer chamber between said outer casing and said outer separator, an inner separator formed as a cylindrical element having a large number of small openings and mounted in said outer separator so as to define an annular intermediate chamber between said outer and inner separators while defining an inner chamber at the inside thereof, a first port means connected with said outer chamber, and a seocnd port means connected with said inner chamber, wherein said outer and inner separators are supported by said outer casing. In such a housing structure for a catalytic converter, it is required that the outer and inner separators should be supported by the outer casing in a manner such that the separators are capable of thermally expanding and contracting relatively freely with respect to the outer casing. Furthermore, it is also required that the outer and inner separators be capable of thermally expanding and contracting relatively freely with respect to each other.